CN108102703B

CN108102703B - Processing method of catalytic diesel oil

Info

Publication number: CN108102703B
Application number: CN201611045477.7A
Authority: CN
Inventors: 王仲义; 崔哲; 彭冲; 刘昶; 吴子明; 孙士可
Original assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Current assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Priority date: 2016-11-24
Filing date: 2016-11-24
Publication date: 2020-06-09
Anticipated expiration: 2036-11-24
Also published as: CN108102703A

Abstract

The invention discloses a processing method of catalytic diesel oil. Cutting a catalytic diesel raw material into a light component and a heavy component; carrying out hydrofining and hydro-upgrading reactions on the light components to obtain gasoline and diesel components; separating the obtained heavy components to obtain tricyclic aromatic hydrocarbon components and non-tricyclic aromatic hydrocarbon components, and performing hydrofining and hydrogenation conversion on the tricyclic aromatic hydrocarbon components to obtain gasoline components and diesel oil components; the two parts of gasoline are mixed to obtain a gasoline product, and the two parts of diesel oil components are mixed to obtain a diesel oil product. The invention can process different types of raw materials selectively and independently through reasonable separation and processing processes, thereby being capable of reasonably utilizing inferior catalytic cracking diesel to produce qualified gasoline and diesel products.

Description

Processing method of catalytic diesel oil

Technical Field

The invention relates to a processing method of catalytic diesel oil, in particular to a method for processing catalytic cracking diesel oil to produce high-quality gasoline and high-quality diesel oil.

Background

Catalytic cracking is the most important secondary process in the petroleum refining industry at present, and is also the core process for heavy oil lightening. With the increasing weight of global petroleum, the processing capacity of the FCC device is continuously improved, various heavy oils are used as raw materials, the main product gasoline with high octane number is obtained through catalytic cracking reaction, and simultaneously, a large amount of catalytic diesel oil with high sulfur, nitrogen and aromatic hydrocarbon contents, low cetane number or cetane index and extremely poor stability is generated. And the requirements of environmental protection laws and regulations are increasingly strict, and the indexes of diesel products are gradually improved, so that strict requirements are imposed on the sulfur content, the aromatic hydrocarbon content, the cetane index and the like in the diesel products. Therefore, while the yield of the poor diesel oil is reduced, a proper method needs to be found for processing the poor diesel oil so as to meet the requirements of product delivery of enterprises.

The catalytic hydrogenation technology has important significance for improving the processing depth of crude oil, reasonably utilizing petroleum resources, improving product quality, improving yield of light oil and reducing atmospheric pollution, particularly has more remarkable importance for catalytic hydrogenation under the condition that the weight of the current petroleum resources is changed and the quality is deteriorated, can improve the hydrogen-carbon ratio in fuel oil products, optimizes product quality and improves emission standard through proper hydrogenation, becomes an indispensable component in the field of petrochemical industry at present, and can be divided into hydrogenation treatment and hydrocracking in the main process.

The catalytic diesel oil has very bad properties, so the current treatment means is single, and in China, the means which can be relied on mainly comprises the combined processing of the catalytic diesel oil and hydrogenation technology, such as the hydrofining after mixing the catalytic diesel oil and the straight-run diesel oil, the hydrocracking after mixing the catalytic diesel oil and the straight-run wax oil and the conversion technology which is used for producing gasoline by independently cracking the catalytic diesel oil in recent years.

CN1955257A introduces a method for producing high-quality chemical raw materials in a large quantity, which mainly mixes poor-quality catalytic cracking diesel oil and hydrogenation raw materials in proportion, and then produces catalytic reforming raw materials and high-quality ethylene raw materials by steam cracking through controlling reaction conditions. Although the catalytic cracking poor diesel oil can be processed, the processing path of poor raw materials is increased and the poor raw materials are converted into high-quality products, the proportion of blended catalytic diesel oil is still limited to a certain extent, the amount of the processable catalytic diesel oil is small, and the consumption of hydrogen for processing the catalytic diesel oil under the high-pressure condition is large.

CN103773455A the invention discloses a combined hydrogenation process of animal and vegetable oil and catalytic diesel, which essentially treats catalytic diesel through hydrofining, and although catalytic diesel can be processed through proper raw material proportion, the amount of catalytic diesel which can be blended is very small due to the limit of diesel product indexes, and the problem of treating a large amount of catalytic diesel of a large catalytic oil refining enterprise can not be thoroughly solved.

CN104611029A discloses a catalytic cracking diesel oil hydro-conversion method, wherein catalytic diesel oil and hydrogen gas are mixed and then enter a hydrofining reactor for hydrofining reaction, and then enter a hydrocracking reactor for hydrocracking reaction. Although the high-octane gasoline can be produced by processing and catalyzing diesel components through a certain catalyst grading action, the chemical hydrogen consumption is relatively high, and the requirement on hydrogen resources of enterprises is relatively high.

Disclosure of Invention

Aiming at the problems in the prior art, the technical problem to be solved by the invention is to provide a hydrocracking process method for processing catalytic diesel oil raw materials. The method comprises the steps of analyzing conventional catalytic diesel oil, cutting and separating to separate tricyclic and higher aromatic heavy components (simultaneously containing a small amount of monocyclic and bicyclic aromatic hydrocarbons with long side chains) and aromatic light components, passing the heavy components through an aromatic separation device to obtain tricyclic aromatic hydrocarbons and non-tricyclic aromatic hydrocarbons, mixing the non-tricyclic aromatic hydrocarbons with the aromatic light components, directly generating high-octane gasoline after the tricyclic aromatic hydrocarbons react, and generating high-cetane diesel oil after the mixed components undergo an open-loop and continuous chain modification reaction. When the catalytic diesel raw material is treated, all the components are separately processed, the pertinence is strong, particularly for conversion reaction, the supplied raw material is changed into the most suitable tricyclic aromatic hydrocarbon, and a high-quality fuel oil product can be produced.

The invention provides a combined process method for processing catalytic diesel oil, which comprises the following steps:

a) cutting and separating the catalytic diesel raw material to obtain a light component and a heavy component;

b) the light component obtained in the step a) is used as raw oil and enters a reactor containing hydrofining and hydro-upgrading catalysts for upgrading reaction, and the obtained reaction effluent is subjected to gas-liquid separation and fractionation processes to obtain upgraded gasoline and upgraded diesel oil;

c) the heavy component obtained in the step a) enters an aromatic hydrocarbon separation device, and tricyclic aromatic hydrocarbon and non-tricyclic aromatic hydrocarbon components in the heavy component are separated;

d) mixing the non-tricyclic aromatic hydrocarbon component obtained in the step c) with the light component obtained in the step b) to carry out modification reaction;

e) the tricyclic aromatic hydrocarbon obtained in the step c) is used as raw oil and enters a reactor containing hydrofining and hydro-conversion catalysts for conversion reaction, and the obtained reaction effluent is subjected to gas-liquid separation, fractionation and other processes to obtain converted gasoline, converted diesel oil and the like;

f) mixing the modified gasoline obtained in the step b) with the converted gasoline obtained in the step e) to obtain a gasoline product; the modified diesel oil in the step b) is directly used as a diesel oil product; the converted diesel oil obtained in the step e) is mixed with the light component in the step a) to carry out upgrading reaction after being circulated, or is mixed with the upgraded diesel oil in the step b) to be used as a diesel oil product.

The initial boiling point of the catalytic diesel oil component in the step a) is generally 160-240 ℃, preferably 180-220 ℃, the final boiling point is generally 320-420 ℃, preferably 350-390 ℃, the aromatic hydrocarbon content is generally more than 50wt%, preferably 60-90 wt%, wherein the tricyclic aromatic hydrocarbon is generally more than 5wt%, preferably more than 10 wt%; the density of the diesel fuel stock is generally 0.91g cm^-3Above, preferably 0.93 g/cm^-3The above.

The catalytic diesel oil raw material can be a catalytic cracking product obtained by processing any basic oil species, for example, the catalytic cracking product can be selected from catalytic diesel oil obtained by processing middle east crude oil, and specifically can be catalytic diesel oil components obtained by processing Iran crude oil, Sauter crude oil and the like.

The cutting separation in the step a) is a conventional gas-liquid separation process, and a flash separation or tray separation mode which is well known in the industry can be adopted, so that the catalytic diesel oil is divided into a light part and a heavy part, and the division point is generally 290-350 ℃, preferably 300-340 ℃ according to the description in the method. The light component is a liquid phase fraction below the division point, and the heavy component is a liquid phase fraction above the division point.

The hydrofining catalyst described in step b) and step e) comprises a carrier and a hydrogenation metal supported thereon. Based on the weight of the catalyst, the catalyst generally comprises 10-35% of metal components in VIB group of the periodic table of elements, such as tungsten and/or molybdenum, calculated by oxide, and preferably 15-30%; group VIII metals such as nickel and/or cobalt are present in amounts of 1% to 7%, preferably 1.5% to 6%, calculated as oxides. The carrier is inorganic refractory oxide, and is generally selected from alumina, amorphous silica-alumina, silica, titanium oxide and the like. The conventional hydrocracking pretreatment catalyst can be selected from various conventional commercial catalysts, such as hydrogenation refining catalysts developed by the Fushu petrochemical research institute (FRIPP), such as 3936, 3996, FF-16, FF-26, FF-36, UDS-6 and the like; it can also be prepared according to the common knowledge in the field, if necessary.

The gas-liquid separation and fractionation processes described in step b) and step e) are well known to those skilled in the art. The gas-liquid separation is a separation process of products in the hydro-upgrading process, and generally mainly comprises a high-pressure separator, a low-pressure separator, a circulating hydrogen system and the like; the fractionation process is a process for further refining a liquid-phase product of gas-liquid separation, and generally mainly comprises a stripping tower, a fractionating tower, a side-line tower and the like.

The hydro-upgrading catalyst in the step b) is a hydro-upgrading catalyst containing a molecular sieve, and refers to a common hydrocracking catalyst or a hydro-upgrading catalyst special for the invention. The hydrogenation modification catalyst comprises hydrogenation active metal, a molecular sieve component and an alumina carrier. The general hydrogenation modification catalyst is composed of hydrogenation active metal components such as Wo, Mo, Co, Ni and the like, a molecular sieve component, an alumina carrier and the like, and the content of the hydrogenation components is 5-40% by weight of the catalyst. The hydro-upgrading catalyst specially used in the invention comprises WO by weight₃(or MoO)₃) 10-30 wt%, NiO (or CoO) 3-15 wt%, molecular sieve 10-40 wt% and alumina 25-60 wt%, wherein the molecular sieve can be Y-type molecular sieve. The main function of the catalyst is to perform a hydrogenation modification process of saturated ring opening but continuous chain breaking on the bicyclic aromatic hydrocarbon, and conventional hydrogenation modification catalysisThe catalyst can be selected from various commercial catalysts, such as 3963, FC-18 and other catalysts developed by FRIPP. Specific hydro-upgrading catalysts may also be prepared as desired according to common general knowledge in the art.

The aromatic hydrocarbon separation device in the step c) is a physical extraction process, and the principle is that the difference of the solubility of solvents for different substances is utilized for extraction, and then the separation process is carried out, wherein the solvents can be sulfolane, furfural, NMP or phenol and the like, the process can be realized by aromatic hydrocarbon extraction or furfural refining devices widely used in industry, a furfural refining unit is preferred, and the operation conditions of the extraction part are as follows: the pressure in the tower is 0.01-0.8 MPa, the temperature is 50-150 ℃, the mass ratio of the solvent is 1-8, and the circulating mass ratio is 0-0.6; the preferable operation conditions are that the pressure in the tower is 0.02-0.1 MPa, the temperature is 60-110 ℃, the mass ratio of the solvent is 2-7, and the circulating mass ratio is 0.2-0.5.

The aromatic hydrocarbon separation device in the step c) can also be an adsorption separation process, and an appropriate molecular sieve is selected or prepared to perform an effective adsorption process by utilizing the difference of the sizes of different types of molecules, and then the steps of desorption separation and the like are performed, so that an ideal component is separated from a non-ideal component.

The hydroconversion catalyst of step e) is a hydroconversion catalyst comprising a molecular sieve, which is a catalyst specifically prepared according to the present process. The hydrogenation conversion catalyst comprises hydrogenation active metal, a molecular sieve component and an alumina carrier. The general hydro-conversion catalyst is composed of hydrogenation active metal components such as Wo, Mo, Co, Ni and the like, a molecular sieve component, an alumina carrier and the like. The hydroconversion catalysts which are specific for the present invention comprise, by weight, WO₃(or MoO)₃) 8-28 wt%, NiO (or CoO) 3-13 wt%, molecular sieve 20-50 wt% and alumina 15-50 wt%.

In the hydroconversion catalyst of step e), the molecular sieve is a small-grain Y-type molecular sieve. The grain size of the small-grain Y-type molecular sieve is 400-600 nm, the infrared total acid is 0.2-0.5 mmol/g, and the proportion of the medium-strong acid is more than 75% (mmol/g)^-1/mmol·g^-1) The unit cell parameter is 2.430-2.436 nm; the pore volume is 0.5-0.7 cm³In each case 2 to 8The proportion of the secondary pore volume of nm to the total pore volume is more than 55%. The Y small crystal grain type molecular sieve has more accessible and exposed acid centers, is favorable for diffusion of hydrocarbon molecules, can improve the preferential conversion capacity of cyclic hydrocarbon, particularly tricyclic aromatic hydrocarbon, directionally saturates and breaks aromatic rings in the tricyclic aromatic hydrocarbon, and produces a gasoline component with a high octane number to the maximum extent. The hydroconversion catalyst containing the small-grain Y-shaped molecular sieve has the main function of performing selective reaction on tricyclic aromatic hydrocarbon in raw materials, and has poor selectivity on non-tricyclic two-ring and monocyclic aromatic hydrocarbon. The Y-type molecular sieve has a certain difference with the conventional Y-type molecular sieve, the grain size of the conventional Y-type molecular sieve is generally 800-1200 nm, and the pore volume is 0.35-0.50 cm³The proportion of the pore volume of the secondary pores of 2-8nm to the total pore volume is generally 30-50%, and the proportion of the medium-strong acid is 50-70%. The hydroconversion catalyst may be used to prepare a satisfactory catalyst in accordance with common general knowledge in the art, as described above.

In the present invention, the term "medium strong acid" is a general concept in the field of catalyst preparation. It employs NH₃TPD, the definition of 150-250 ℃ desorption is weak acid, the definition of 250-400 ℃ desorption is medium strong acid, the definition of 400-500 ℃ desorption is strong acid,

in step e), the hydroconversion catalyst preferably adopts a catalyst grading filling scheme. The hydroconversion catalyst comprises at least two catalyst beds, and according to the contact sequence of the catalyst beds and reaction materials, the unit cell parameter of a Y-shaped molecular sieve in the catalyst of an upstream bed is generally 2.430-2.433 nm, and the infrared total acid is 0.2-0.35 mmol/g; the unit cell parameter of the Y-type molecular sieve in the catalyst in the downstream bed layer is generally 2.433-2.436 nm, and the infrared total acid is 0.35-0.5 mmol/g. Compared with the catalyst in the upstream bed layer, the proportion of the secondary pores in the catalyst in the downstream bed layer to the total pore volume is 5-20 percent lower, and the content of the Y-type molecular sieve is 5-20 percent higher. The modification treatment process of the Y-type molecular sieve satisfying the requirement can be performed by using the conventional technology in the art, for example, the method described in CN104588073A can be referred to for the modification treatment of the Y-type molecular sieve.

According to the difference between the unit cell parameters of the Y-type molecular sieve and the total infrared acid amount, the catalysts can be matched according to the difference of the activity. Therefore, the hydrogenation performance and the cracking performance of the catalyst can be more reasonably excessive along the flowing direction of the reaction materials, the hydrogenation and cracking processes are more specifically carried out on reactants, particularly tricyclic complex aromatic hydrocarbons, the middle ring is subjected to saturation cracking, and the reactants are further directionally converted into gasoline components with high octane number to the greatest extent, so that the content of polycyclic aromatic hydrocarbons in the product can be greatly reduced, and the selectivity of the hydrogenation conversion is further improved.

The catalyst filled by grading technology is first contacted with the heavy catalytic diesel oil component containing great amount of tricyclic aromatic hydrocarbon and proper amount of bicyclic aromatic hydrocarbon for reaction. Because the polarity of the tricyclic aromatic hydrocarbon is strong, the adsorption capacity is strong, and the cracking difficulty is not large, the upstream catalyst has proper molecular sieve content and secondary pore proportion, the acidity is moderate, the tricyclic aromatic hydrocarbon can be effectively and directly converted into a high-octane gasoline component containing monocyclic aromatic hydrocarbon, and the molecular sieve and secondary pore proportion in the downstream catalyst is slightly high. The acidity is strong, and the bicyclic aromatic hydrocarbon can be further converted into a high-octane gasoline component containing monocyclic aromatic hydrocarbon, so that most of the bicyclic aromatic hydrocarbon can be directly converted into a target product according to the reaction difficulty of different components in the raw materials by adopting the catalyst grading scheme, and the selectivity is further improved.

The reaction conditions of the modification reaction in the step b) are as follows: the volume space velocity is 0.5-4.0 h^-1Preferably 0.8 to 2.5 hours^-1(ii) a The hydrogen partial pressure is 4-13 MPa, preferably 6-10 MPa; the volume ratio of the hydrogen to the oil at the inlet is 300: 1-800: 1, preferably 400: 1-700: 1; the reaction temperature is 340-410 ℃, preferably 360-400 ℃.

The reaction conditions of the conversion reaction in step c) are as follows: the volume space velocity is 0.5-4.0 h^-1Preferably 0.8 to 2.5 hours^-1(ii) a The hydrogen partial pressure is 4-13 MPa, preferably 6-10 MPa; the volume ratio of the hydrogen to the oil at the inlet is 300: 1-800: 1, preferably 400: 1-700: 1; the reaction temperature is 360-430 ℃, and preferably 380-420 ℃. According to the difference of cut point and aromatic hydrocarbon distribution, the conversion reaction is controlled to be larger than the cut point according to the content of tricyclic aromatic hydrocarbon in the raw materialThe fractional conversion, generally controlled mass conversion, is not higher than 70%, preferably not higher than 50%.

The gasoline product and the diesel oil product in the step f) are high-quality blending components which can enter a blending pool for blending finished oil.

Compared with the prior art, the catalytic diesel oil processing method has the following advantages:

1. the catalytic diesel oil with high content of aromatic hydrocarbon is processed, and the components containing tricyclic aromatic hydrocarbon and non-tricyclic aromatic hydrocarbon are independently processed after the light and heavy separation cutting process and the aromatic hydrocarbon separation device, so that the tricyclic aromatic hydrocarbon which is most suitable as a hydrogenation conversion raw material can be subjected to conversion reaction. The preparation technology of the catalyst and the parameter control of the process are combined, the high-octane gasoline component can be produced to the maximum extent, and the non-tricyclic aromatic hydrocarbon mixture can be subjected to the saturated ring opening and hydrogenation processes, so that the high-cetane diesel component can be produced to the maximum extent. The method can process different types of raw materials independently in a targeted manner through reasonable raw material separation and processing processes, simplifies the complex petroleum refining process, and maximizes the processing suitability and pertinence of each component while considering the processing difficulty when processing poor-quality catalytic diesel oil, thereby having great advantages.

2. The method deeply couples the separation, the hydro-upgrading and the hydro-conversion in the process flow, and obtains ideal comprehensive processing effect on the basis of pertinently treating raw materials and improving the product quality. Although each unit has stronger independence in the description process, different units can be organically combined and shared in practical application, so that the method has the advantages of equipment saving, low operation cost and the like, and simultaneously, due to the improvement of a heat exchange system caused by combination, the energy consumption of the device is reduced to a certain extent, the investment is reduced, and the method has wide application prospect.

3. According to the method, a new conversion catalyst with stronger pertinence is developed on the basis of the original catalytic diesel oil hydroconversion catalyst, and the method is also a great embodiment of technical progress, can provide more catalytic selection directions for enterprises, and brings more visual economic benefits. The small crystal grain molecular sieve used by the hydro-conversion catalyst has large specific surface, particularly obviously increased external surface area, sharply increased ratio of surface atomic number to volume atomic number, shortened pore passage and increased exposed pore openings, thereby having higher reaction activity and surface energy and showing obvious volume effect and surface effect. Specifically, the following aspects are provided: the increase of the external surface area of the molecular sieve enables more active centers to be exposed, effectively eliminates the diffusion effect, and enables the catalyst efficiency to be fully exerted, thereby improving the reaction performance of macromolecules; the surface energy is increased, so that the adsorption capacity of the molecular sieve is increased, the adsorption speed is accelerated, and the effective adsorption capacity of the molecular sieve is improved; the small-crystal molecular sieve has short pore passage, small diffusion resistance in the crystal and huge external surface area, so that more pores of the small-crystal molecular sieve are exposed outside, which is beneficial to the rapid inlet and outlet of reactant or product molecules, can prevent or reduce the formation of carbon deposition due to the accumulation of the product in the pore passage, and improves the turnover rate of the reaction and the service life of the molecular sieve; has uniform radial distribution of the skeleton components, thereby improving activity and selectivity; the method is more beneficial to the realization of the modification technology after the synthesis of the molecular sieve; for molecular sieve supported metal catalysts, the use of small crystallite molecular sieves is beneficial in increasing the effective loading of the metal component and improving the dispersion properties of the metal component. In addition, the proportion of secondary pores in the molecular sieve can be further increased through subsequent modification treatment. The unblocked molecular sieve pore structure is more beneficial to macromolecule adsorption reaction and desorption, the directional hydro-conversion capability of macromolecule heavy aromatics is greatly enhanced, and the saturation and cracking of the intermediate ring can make the high-octane gasoline component in the product more.

Drawings

FIG. 1 is a schematic flow diagram of the process of the present invention.

Detailed Description

The combined process of the present invention will be described in detail with reference to the accompanying drawings. Only the main description of the process flow is given in fig. 1, and some necessary equipment and vessels are also omitted from the schematic.

As shown in figure 1, the combined process flow for processing catalytic diesel oil of the invention is as follows: after a catalytic diesel raw material 1 enters a separator 2, a light component 3 is obtained at the upper part, a heavy component 12 is obtained at the lower part, the light component 3 is mixed with hydrogen 4 and then enters a hydro-upgrading reactor 5 to be in contact reaction with a catalyst, a reaction effluent 6 enters a separation and fractionation system 7, a gas phase 8 is discharged from the upper part, upgraded gasoline 9 is obtained at the middle part, and upgraded diesel 10 is obtained at the bottom; the heavy component 12 enters an aromatic hydrocarbon separation device 13, the non-tricyclic component 14 obtained at the upper part and the light component 3 enter a modified reactor 5 together, the tricyclic component 15 obtained at the bottom part is mixed with hydrogen 16 and then enters a hydro-conversion reactor 17 to be in contact reaction with graded conversion catalysts (A and B), a reaction effluent 18 enters a separation and fractionation system 19, the upper part discharges a gas phase 20, the middle part obtains converted gasoline 21, and the converted diesel oil 22 obtained at the bottom part is mixed with the light component 3 and the non-tricyclic component 14 to react together or is mixed with the modified diesel oil 10 to obtain qualified diesel oil 11 before being circulated back to the reactor 5; the modified gasoline 9 and the converted gasoline 21 are mixed to obtain qualified gasoline 23.

The combined process of the present invention is further illustrated by the following specific examples.

The aromatic separation apparatus referred to in the following examples and/or comparative examples were operated under the following conditions: furfural is selected as an extraction solvent, the column pressure is controlled to be 0.04-0.13 MPa, the temperature is 50-90 ℃, the solvent ratio is 3, the circulation ratio is 0.3, and different types of aromatic hydrocarbon can be ideally separated.

Example 1

The combined process flow shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is 290 ℃, a furfural refining device is selected for separating heavy aromatics, and the target products are high-quality gasoline and diesel oil. The catalysts used in the examples are commercial catalyst FF-36 hydrotreating catalyst, 3963 hydro-upgrading catalyst and special hydro-conversion catalysts A and B (the catalyst composition comprises metal oxide and Y-type molecular sieve, and the balance is alumina) of the technology.

Example 1

The technological process shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is 300 ℃, and target products are high-quality gasoline and diesel oil. The catalysts used in the examples were a commercial catalyst FF-36 hydrotreating catalyst, a 3963 hydro-upgrading catalyst, and a hydroconversion catalyst a.

Example 2

The combined process flow shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is 300 ℃, and the target products are high-quality gasoline and diesel oil. The catalysts used in the examples were a commercial catalyst FF-36 hydrotreating catalyst, a 3963 hydro-upgrading catalyst, and a special hydroconversion catalyst a and B of the present technology.

Example 3

The technological process shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is 310 ℃, and target products are high-quality gasoline and diesel oil. The catalysts used in the examples were commercial catalysts FF-36 hydrotreating catalyst, 3963 hydro-upgrading catalyst, and hydroconversion catalysts a and B.

Comparative example 1

The technological process shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is 300 ℃, and target products are high-quality gasoline and diesel oil. The catalysts used in the comparative examples were a commercial catalyst FF-36 hydrotreating catalyst, a 3963 hydro-upgrading catalyst, and a conventional hydroconversion catalyst C.

Comparative example 2

Comparative example 2 is a conventional catalytic diesel hydroconversion process, catalytic diesel is selected as a raw material for hydrogenation production, and the target products are high-quality gasoline and common diesel. The catalysts used in the comparative examples were a commercial catalyst FF-36 hydrotreating catalyst and a conventional hydroconversion catalyst C.

The properties of the specific and conventional hydroconversion catalysts are shown in Table 1, the properties of the feedstock are shown in Table 2, the operating conditions are shown in Table 3, and the properties of the main products are shown in Table 4.

TABLE 1 Main physicochemical Properties of catalysts tailored by this technology

TABLE 2 raw oil Properties Table

TABLE 3 reaction conditions

TABLE 3 reaction conditions

As can be seen from the examples and comparative examples in tables 2 and 3, the present technology has a great advantage in hydrogen consumption for the production of gasoline by processing a large amount of catalytic diesel.

TABLE 4 Main Properties of the product

As can be seen from the above examples, the properties of both the naphtha and the diesel oil produced by the present invention have certain advantages compared with the comparative examples on the basis of large amount of processed catalytic diesel oil and low hydrogen consumption.

It can be seen from the above examples and comparative examples that the catalytic diesel raw material is cut and separated by the method and then processed respectively, so that the poor-quality diesel components can be treated to the maximum extent, the diesel-steam ratio can be flexibly adjusted from the aspect of balance or saving of hydrogen resources according to the actual conditions of enterprises, and the production is carried out according to the change of market demands.

The separation, the hydro-upgrading and the hydro-conversion are combined in the process flow, and an ideal comprehensive processing effect is obtained on the basis of pertinently treating raw materials and improving the product quality. Although each unit has stronger independence in the description process, different units can be combined organically and shared in practical application, so that the method has the advantages of equipment saving, low operation cost and the like, and simultaneously, due to the improvement of a heat exchange system caused by combination, the energy consumption of the device is reduced to a certain extent, the investment is reduced, and the method has wide application prospect.

Claims

1. A combined process for processing catalytic diesel oil, comprising the steps of:

a) cutting and separating the catalytic diesel raw material to obtain a light component and a heavy component; the cutting temperature of the light component and the heavy component is 290-350 ℃;

e) the tricyclic aromatic hydrocarbon obtained in the step c) is used as raw oil and enters a reactor containing hydrofining and hydro-conversion catalysts for conversion reaction, and the obtained reaction effluent is subjected to gas-liquid separation and fractionation processes to obtain converted gasoline and converted diesel oil;

f) mixing the modified gasoline obtained in the step b) with the converted gasoline obtained in the step e) to obtain a gasoline product; the modified diesel oil in the step b) is directly used as a diesel oil product; the converted diesel oil obtained in the step e) is mixed with the light component in the step a) to carry out upgrading reaction after being circulated, or is mixed with the upgraded diesel oil in the step b) to be used as a diesel oil product;

wherein the hydroconversion catalyst comprises hydrogenation active goldA metal, Y-type molecular sieve and an alumina carrier; the particle size of the Y-type molecular sieve is 400-600 nm, the infrared total acid is 0.2-0.5 mmol/g, the proportion of the medium strong acid is more than 75%, and the unit cell parameter is 2.430-2.436 nm; the pore volume is 0.5-0.7 cm³The proportion of the secondary pore volume of 2-8nm in the total pore volume is more than 55%;

the hydro-conversion catalyst in the step e) comprises at least two catalyst bed layers, and compared with the catalyst in the upstream bed layer, the proportion of 2-8nm secondary pores in the catalyst in the downstream bed layer to the total pore volume is 5-20% lower, and the content of the Y-type molecular sieve is 5-20% higher.

2. The combined process of claim 1, wherein the catalytic diesel feedstock of step a) has an initial boiling point of 160-240 ℃, an end boiling point of 320-420 ℃, and an aromatics content of greater than 50 wt%.

3. The combined process of claim 2, wherein the catalytic diesel feedstock of step a) has an initial boiling point of 180-220 ℃, an end boiling point of 350-390 ℃, and an aromatics content of 60-90 wt%.

4. The combined process of claim 2 or 3, wherein the catalytic diesel feedstock has a density of 0.91 g-cm^-3The above.

5. The combined process of claim 1 wherein the cut temperature of the light and heavy components is from 300 ℃ to 340 ℃.

6. The integrated process of claim 1 wherein said hydrofinishing catalyst comprises a support and a hydrogenation metal supported thereon; based on the weight of the catalyst, the catalyst comprises 10-35% of VIB group metal components in the periodic table of elements by oxide and 1-7% of VIII group metal by oxide; the carrier is an inorganic refractory oxide.

7. The combined process of claim 1 wherein said hydro-upgrading catalyst of step b) comprises a hydrogenation-active metal, a molecular sieve component and an alumina support; the hydro-upgrading catalyst comprises WO based on the weight of the catalyst₃Or MoO₃10-30 wt%, NiO or CoO 3-15 wt%, molecular sieve 10-40 wt% and alumina 25-60 wt%.

8. The integrated process of claim 1 wherein said aromatics separation in step c) is by furfural refining and the operating conditions of the extraction section are as follows: the pressure in the tower is 0.01-0.8 MPa, the temperature is 50-150 ℃, the solvent ratio is 1-8, and the circulation ratio is 0-0.6.

9. The integrated process of claim 8 wherein said operating conditions are: the pressure in the tower is 0.02-0.1 MPa, the temperature is 60-110 ℃, the solvent ratio is 2-7, and the circulation ratio is 0.2-0.5.

10. The combined process according to claim 1, wherein the hydroconversion catalyst of step e) comprises, by weight, WO₃Or MoO₃8-28 wt%, NiO or CoO 3-13 wt%, Y-type molecular sieve 20-50 wt% and alumina 15-50 wt%.

11. The combined process of claim 1, wherein the unit cell parameters of the Y-type molecular sieve in the catalyst of the upstream bed layer are 2.430-2.433 nm and the total infrared acid is 0.2-0.35 mmol/g in the contact sequence with the reaction materials; the unit cell parameter of the Y-type molecular sieve in the downstream bed layer catalyst is 2.433-2.436 nm, and the infrared total acid is 0.35-0.5 mmol/g.

12. The integrated process of claim 1 wherein said upgrading of step b) is carried out under the reaction conditions: the volume space velocity is 0.5-4.0 h^-1The hydrogen partial pressure is 4-13 MPa, the inlet hydrogen-oil volume ratio is 300: 1-800: 1, and the reaction temperature is 340-410 ℃.

13. The integrated process of claim 12 wherein said upgrading of step b) is carried out under reaction conditions selected from the group consisting of: the volume space velocity is 0.8-2.5 h^-1The hydrogen partial pressure is 6-10 MPa, the inlet hydrogen-oil volume ratio is 400: 1-700: 1, and the reaction temperature is 360-400 ℃.

14. The integrated process of claim 1 wherein said converting reaction of step e) is carried out under reaction conditions selected from the group consisting of: the volume space velocity is 0.5-4.0 h^-1The hydrogen partial pressure is 4-13 MPa, the volume ratio of hydrogen to oil at the inlet is 300: 1-800: 1, and the reaction temperature is 360-430 ℃.

15. The integrated process of claim 14 wherein said converting reaction of step e) is carried out under reaction conditions selected from the group consisting of: the volume space velocity is 0.8-2.5 h^-1The hydrogen partial pressure is 6-10 MPa, the volume ratio of hydrogen to oil at the inlet is 400: 1-700: 1, and the reaction temperature is 380-420 ℃.

16. The integrated process of claim 1 wherein step e) controls the mass conversion of the temperature cut above the cut point of step a) to not more than 60%.